Police wearing plastic body armour and gas masks marched on demonstrators near the Georgian parliament in the morning, chasing off thousands of protesters with tear gas, rubber bullets and truck-mounted water cannons.

Protesters later regrouped in Tbilisi's Old Town and were dispersed again by riot police firing tear gas and water cannons. Around 250 people were taken to hospital, officials said.

Opposition leaders bitterly criticised President Mikhail Saakashvili's government, a staunch US ally, for using violence to put down the protests. They said its actions proved their accusations that he was an authoritarian and corrupt leader.

''Today's events have shown that Georgia is being run by a terrorist organisation led by the terrorist Mikhail Saakashvili,'' opposition leader Goga Khaindrava told journalists following a brief spell under arrest.

The government struck back, alleging that former imperial master Russia was behind the protests and promising to produce evidence of opposition leaders' links to Moscow-based spies.

Relations between Georgia and Russia hit all-time lows last year over Saakashvili's desire to join NATO and his drive to regain sovereignty over two breakaway pro-Russian provinces.

Georgia also recalled its ambassador from Moscow for consultations today and summoned Russia's envoy to Tbilisi for talks.

''Russia has launched a wide-scale attack against Georgia,'' Georgian Parliament Minister Givi Targamadze said on television.

Opposition members had ''sold their motherland for a specific price,'' he added.

Opposition leaders, who have not questioned Saakashvili's pro-Western line, called the accusations baseless and laughable.

They said the Georgian Ministry of Internal Affairs (MVD) was responsible for the ''wild'' accusations of Russian intervention.

''The MVD could not have come up with anything more stupid,'' Konstantin Gamsakhurdia, son of first Georgian president Zviad Gamsakhurdia, told Interfax.

POLICE DRESSED IN BLACK The health minister said 250 people were taken to hospital after police used force for the first time since the protests began last Friday, the biggest civil demonstration since a peaceful revolution swept Saakashvili to power in 2003.

''More than 50 have already been released. We have a few trauma cases, but basically it's people poisoned by tear gas,'' Health Minister David Tkeshelashvili said.

Police dressed in black and wearing balaclavas had earlier beaten and punched protesters before a water cannon sprayed the streets, witnesses said. Clouds of tear gas filled the area in central Tbilisi and choked the crowds.

''Only a fascist power could do this,'' Nana Abuladze, 56, said between vomiting. She had been protesting when the police fired the tear gas.

''The authorities have used weapons against peaceful demonstrators and therefore the authorities will get what they deserve from the people,'' opposition leader Kakha Kukava was quoted as saying by Interfax news agency.

Saakashvili has pursued Western-style economic reforms and closer links with Washington but critics say living standards have not improved for many Georgians and corruption and human rights violations remain a problem in the former Soviet state.